Thursday, April 5, 2012

Paper: Temperature records show 'predominantly natural fluctuations'

Published this week in the NIPCC Report:

One Hundred Years of Global Temperature Change

Reference: Ludecke, H.-J., Link, R. and Ewert, F.-K. 2011. How natural is the recent centennial warming? An analysis of 2249 surface temperature records. International Journal of Modern Physics C 22: 10.1142/S0129183111016798.

Working with 2249 globally-distributed monthly temperature records covering the period 1906-2005, which they obtained from NASA's Goddard Institute for Space Studies, Ludecke et al. (2011) evaluated "to what extent the temperature rise in the past 100 years was a trend or a natural fluctuation."

According to the authors, "the mean of all stations shows 0.58°C global warming from 1906 to 2005," but they say that "if we consider only those stations with a population of under 1000 and below 800 meters above sea level, this figure drops to 0.41°C." In addition, they note that "about a quarter of all records show falling temperatures," which in itself, in their words, "is an indication that the observed temperature series are predominantly natural fluctuations," where the word natural means that "we do not have within a defined confidence interval a definitely positive anthropogenic contribution." And continuing to explore this aspect of their analysis, they evaluated - with a confidence interval of 95% - the probability that the observed global warming from 1906 to 2005 was a natural fluctuation, finding that probability to lie "between 40% and 70%, depending on the station's characteristics," while "for the period 1906 to 1955 the probabilities are arranged between 80% and 90% and for 1956 to 2005 between 60% and 70%."

Based on their several findings, the authors write in the final sentence of the abstract of their paper that the strongest statement they can make on the subject is that "only a marginal anthropogenic contribution cannot be excluded," which suggests to us that if there is a CO2-induced warming signal hidden somewhere in the global temperature data of the Goddard Institute for Space Studies, it must be relatively small, as is suggested by the observation-based analyses of Idso (1998), Lindzen and Choi (2009, 2011) and Scafetta (2012).

Additional References

Idso, S.B. 1998. CO2-induced global warming: a skeptic's view of potential climate change. Climate Research 10: 69-82.

Lindzen, R.S. and Choi, Y.-S. 2009. On the determination of climate feedbacks from ERBE data. Geophysical Research Letters 36: 10.1029/2009GL039628.

Lindzen, R.S. and Choi, Y.-S. 2011. On the observational determination of climate sensitivity and its implications. Asia-Pacific Journal of Atmospheric Sciences 47: 377-390.

Scafetta, N. 2012. Testing an astronomically based decadal-scale empirical harmonic climate model versus the IPCC (2007) general circulation climate models. Journal of Atmospheric and Solar-Terrestrial Physics: 10.1016/j.jastp.2011.12.005.
 

3 comments:

  1. In my view we need to focus on the assumed problem, namely carbon dioxide and, to a lesser extent, methane perhaps. If I refer to trace gases take it to mean these, because I refuse to call them greenhouse gases.

    We have what we have in the Earth's total system. Somehow, in some way we may never fully understand, a long-term near equilibrium situation has developed. We have some energy being generated in the core, mantle and crust, most likely by fission I think, but I won't go into that. But it does set up a temperature gradient from the core to the surface which is very stable below the outer kilometre or so of the crust. However, it may vary in long-term natural cycles that have something to do with planetary orbits. Likewise, the intensity of solar radiation getting through the atmosphere to the surface may also vary in natural cycles which may have something to do with planetary influences on the Sun, and on the eccentricity of Earth's orbit and on cosmic ray intensity and on cloud cover, ENSO cycles etc.

    There is much to be learned about such natural cycles, and we have seen papers by Nicola Scafetta for example which appear to provide compelling evidence of the natural cycles. I believe that in fact such natural cycles are quite sufficient to explain all observed climate change, including what has happened in the last half century or so, right up to the present. The world has just been alarmed because the 1000 year cycle and the 60 year cycle were both rising around 1970 to 1998, just as they did by about the same amount 60 years earlier, and 60 years before that and no doubt further back. We cannot escape the obvious fact that there is a ~1000 year cycle which is due for another maximum within 50 to 200 years. Then there will be 500 years of falling temperatures.

    But the central issue is whether or not trace gases are really having any effect at all on climate.

    In my paper I have explained the physics of heat transfer and demonstrated why trace gases cannot have any effect whatsoever on what we call climate.

    Climate may be thought of as the mean of temperature measurements, usually made in the air between 1.5 and 2 metres above the ground. Thermometers are affected by the thermal energy in that air near the surface. As you can read here thermal energy is distinct from heat. It is transferred by molecular collision processes (conduction and diffusion,) by physical movement (convection) and by radiation. . The energy in radiation is not thermal energy. Thermal energy is first converted to electromagnetic (radiated) energy and then that EM energy has to be converted back to thermal energy in a target. Hence, in a sense thermal energy only appears to be transferred by radiation.

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  2. (continued)

    The Second Law of Thermodynamics (SLoT) tells us that in any (one way, independent) spontaneous process, entropy cannot decrease unless external energy is added. There are no two ways about it. If spontaneous radiation emanates from a cooler object (or atmosphere) its EM energy cannot be converted back to thermal energy in a warmer target, such as Earth's surface. This point is not debatable. A violation of the SLoT cannot be excused on the grounds that there will be some subsequent independent process (maybe not even radiation) which will transfer more thermal energy back to the atmosphere. If you disagree, you are mistaken.

    However, the radiation from a cooler body can affect the radiative component of the cooling of a warmer body. Although such radiation undergoes what I call "resonant scattering" this does involve the "resonators" in the warmer body and uses up some of its radiating capacity. Because the incident radiation supplies the energy, the warmer body does not need to convert an equivalent amount of its own thermal energy. Hence it cools more slowly.

    But, the resonating process involves all the (potential) different frequencies in the incident radiation. There will be far less effect when there are limited frequencies as is the case for radiation from a trace gas in the atmosphere. Furthermore, the effect depends on the temperature of that gas and is less when it is cooler. It is far less from space (equivalent to about 2.7K) and so there is no slowing of cooling for that portion of radiation which gets through the atmospheric window.

    The remaining radiation (when we look at net figures, not all that backradiation) represents less than a third of all the cooling processes from the surface to the atmosphere. The other non-radiative processes can, and will, simply speed up in order to compensate, because they do so if the temperature gap increases. There are further reasons discussed in Q.3 in the Appendix of my paper.


    So there is no overall effect at all due to trace gases on the rate of cooling of the surface. Thus there can be no effect upon climate.

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  3. Doug Cotton,

    Thanks for the summary of your paper. Agree that conventional greenhouse theory violates the 2nd law as well as the 1st law:

    http://hockeyschtick.blogspot.com/2010/06/why-conventional-greenhouse-theory.html

    http://hockeyschtick.blogspot.com/2010/07/why-greenhouse-theory-violates-2nd-law.html

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